Automatic conflict detection and reolution in metrorail ytem: evaluation approach for MARCO EU project G.F. D'Addio, M. Mazzucchelli, S. Savio Dipartimento di Ingegneria Elettrica, Univerita di Genova, Via all'opera Pia, 11 a-16145 Genova, Italy Email: tefano@die. unige. it Abtract The European Union (EU) i promoting, within Telematic Application Programme, everal Reearch and Development (R&D) project, devoted to Tranport Sector, containing high profile telematic technology applied to planning and operational tak. In particular, MARCO, acronym of Multilevel Advanced Railway Conflict reolution and Operation control, concern the development of telematic tool for traffic conflict management: the project purpoe i to develop a et of tool, algorithm and technologie for the Conflict Detection and Reolution (CDR) in a wide range of real time application within railway and metre network. In order to ae MARCO functionality in metrorail application, a CDR demontrator will be developed and intalled in Milan Underground at Seto terminu, and ubequently teted and evaluated during traffic real operation through uitable procedure. In thi paper the author preent a propoal for evaluating, on the bai of objective indicator, the performance of the above mentioned demontrator, taking into account both a comparion between hitorical field data and actual operation, and a comparion between actual operation and imulated operation (without MARCO) in preence of the ame traffic condition. 1 Introduction In the Fourth Framework R&D Programme, the Telematic Application Programme (TAP) ha to promote the competitivene of European
462 Urban Tranport and the Environment for the 21t Century indutry, to improve the efficiency of ervice of public interet, and to timulate job creation through the development of new telematic ytem and ervice. At the beginning of the programme, European yearly pent over 500 billion ECU on tranport, and the economic loe aociated with traffic delay and accident were etimated at 150 billion ECU annually. Then, new olution were needed to reduce the high level of accident, congetion and pollution caued by today' ever increaing traffic volume. Tangible benefit are expected, through the application of telematic ytem, on indicator uch a quality of ervice, travel time, number of accident, regularity of public tranport, pollution. In particular, MARCO project, which i involved in Tak 3.27 - Control Centre of the Telematic Workprogramme, ha to develop a telematic baed upport environment in rail and metrorail control centre to enhance ytem efficiency through a better regulation of traffic operation. Thi improvement will be realied by mean of advanced oftware tool, which will be introduced in modern Traffic Management Sytem (TMS), in order to manage and olve perturbed traffic condition. In thi paper the author preent the evaluation activitie carried out during the project development and define ome performance meaure, which could be utilied in metro verification ite in order to ae if the initial project objective are reached. 2 Overview of the project Several factor affect traffic regularity and the reulting delay vary from a few econd to everal hour. Such perturbed traffic condition are uually managed by human operator (dipatcher) but, a traffic complexity increae, an advanced oftware ytem could be very ueful in order to help the dipatcher in the deciion proce or to perform automatically conflict olution [1]. Referring to a multi-layered Superviion Sytem for Traffic Control, the project will improve Conflict Reolution Sub-ytem (CRS) for: Global Area Network (GAN) level, which include many High Traffic Area. High Traffic Area (HTA) level, which include complex junction, tation and line. Underground level, developed for it mot complex operational ituation (end line). The project, which tarted at the beginning of 1996, involve everal partner coming from metro and railway adminitration, indutrie and univeritie and it i co-ordinated by ABB Daimler-Benz Tranportation (Adtranz Italy). Starting from the knowledge of the procedure for
Urban Tranport and the Environment for the 21t Century 463 conflict detection and reolution utilied within the exiting traffic Management Control Centre, the project ha identified, at firt, the method ued by the dipatcher and the poible benefit due to the introduction of a computeried ytem, formaliing the reult in the Uer Requirement and Contraint Definition document. The econd phae of the project ha developed the Functional Analyi and the Sytem Architecture. During the third phae, the algorithm development and their aement have been carried out in order to highlight the mot promiing optimiation technique to be utilied in the traffic detection and reolution proce. The major emphai in the Fourth Framework i on verifying the benefit of telematic application for olving real-world problem. To thi aim a et of demontrator (prototype) will be developed, both in real and imulated environment. The demontrator functionality in the preence of typical conflict, ditinguihed by level of dipoition a hown in Table 1, will be verified. Table 1 - Typical conflict Type of conflict Train headway conflict (track uage) Train meeting conflict Train paing conflict Locked track Fouling of gauge Route conflict (in interlocking ytem) Platform (berth) conflict Train connection Re-routing conflict Local load peak conflict on a line Local load peak conflict in a junction Impact of conflict in neighboured railway Conflict with additionally inerted train Roter conflict Convergence conflict HTA Junction S S &4AT HTA Line Metro S S
464 Urban Tranport and the Environment for the 21t Century In the following Table 2 MARCO experimental ite are hown. Table 2 - Verification ite Verification Site Milan Metro - Seto Terminu (Italy) FS Milan Junction (Italy) VR Huopalahti Junction (Finland) NMBSDB Connection (Belgium) MARCO Level Underground HTA HTA GAN In order to aure that the project, during all it life, i well managed and each tep i coherent with the other, a pecific tak, Evaluation, ha been developed in parallel with the project. 3 The role of verification and evaluation The verification proce aim to finally provide realitic guidance to the way the experimental cheme will operate and be ued in normal, fullcale application, to determine it uer and wider acceptability, to inform potential invetor of commercial performance and market potential, and authoritie of the wider ocial effect, cot and benefit [2], [3]. In MARCO, the relationhip and information exchanged during verification among different workpackage are hown in Figure 1: developer have to build the demontrator, integrating the ubytem previouly developed in order to meet the requirement tated by the uer, verification activitie have to tet the operating performance of each application and to make the application acceptable by end uer, and evaluation ha to determine the value of the application in comparion with alternative application andor with a reference cae, analying reult of related experiment and deriving recommendation for deciion maker. The reponible partner of the evaluation activitie, developed in MARCO, i the Dipartimento di Ingegneria Elettrica - Univerita degli Studi di Genova (UGDIE), which i not directly involved in any ytem development phae in order to guarantee a high level of independence. The evaluation objective are: to ae that MARCO application uccefully olve the problem of conflict detectionreolution in a wide range of real time application within railway and metro network; to guarantee the quality apect of the project development. The Evaluation Plan, developed by the Conortium, ha formalied ome verification objective, ummaried in the following bullet lit, which
Urban Tranport and the Environment for the 21t Century 465 have to be taken into account during the verification activity on the bai of aociated indicator: capability of detection; capability of reolution; improvement of traffic regularity; MMI with control feature for all reolution meaure; diplay capability for network layout, load tatu and train data. Evaluation Workpackage Tet Reult Aement Evaluation Report ^- -v. MARCO VERIFICATION Demontrator with Verification Objective ^ Acceptance Criteria Feedback Verification Report Figure 1 - Relationhip during verification The final goal of the verification activitie i to make available a et of reult allowing the evaluation team to analye the traffic performance on the bai of uitable predefined indexe before and after MARCO during an adequate time period, which depend on the nature of the controlled area. It i worth noting that all the objective have not to be aeed in each verification ite, and for thi reaon it i mandatory to define in detail the purpoe of each demontrator in term of the objective to be verified. In particular, a far a Milan Metro demontrator i concerned, the impact due to the introduction of MARCO tool on traffic regularity ha to be analyed and the improvement aeed.
466 Urban Tranport and the Environment for the 21t Century 3.1 Milan Metro Demontrator Milan Metro demontrator will run on ite, but an evaluation activity imply baed on the comparion between field tet and a data collection, a priori defined, may not lead to a atifactory aement of the performance. In fact, in the real operation of the demontrator, the diturbance come from the tochatic behaviour of the traffic and cannot be controlled at all (i.e. it i not poible to repeat the ame identical condition within different experiment). For thi reaon a laboratory evaluation of the demontrator hould be provided, before performing the field tet, allowing to: tet the demontrator beforefieldoperation; # ae the demontrator performance in preence of well defined and repeatable event. By thi way the aement of the Milan Metro demontrator will have two contribution: laboratory - imulated aement and field tet aement. During the field teting, the demontrator will be located in the terminu of Seto. The final uer of the demontrator i the dipatcher who ha in charge the interlocking command conole of Seto terminu and ha baically a read only interaction with the demontrator, which give him: an updated uggetion of the command to be executed by mean of the interlocking conole; a hort term forecat of the next arrival to the terminu; a hort term forecat of the behaviour of the terminu, a a conequence of the application of the above command. The command are decribed a a timed lit of part routing to be executed, while the forecat i decribed a a prediction of train arrival and departure time. By an operational point of view, the dipatcher i free to follow or not the timed command equence uggeted by the demontrator. If the dipatcher doe not correctly follow the uggetion of the ytem, the forecat i no longer valid. The baic aim of Milan Metro demontrator i to ugget to the dipatcher a regulation policy of the terminu allowing to obtain: on chedule departure timing, even if arrival timing are not regular (if arrival irregularity i not too big and may be fully recovered by terminu operation capability); a mooth recovery of the departure irregularity, in the cae of trong perturbation of arrival time. The evaluation of the demontrator will be carried out by analying the improvement of traffic regularity inide the terminu area, meaured by mean of adequate performance indicator, a uggeted by the author in the next paragraph.
Urban Tranport and the Environment for the 21t Century 467 4 Performance indicator for Milan Metro In thi paragraph the performance indexe which may be utilied for the evaluation of Milan Metro demontrator are decribed. I Storage track 1 Storage track 3 Figure 2 - Seto terminu layout (a = arrival, d = departure) According to the phyical layout of Seto terminu, depicted in Figure 2, and to the objective of the demontrator, defined in the previou paragraph, the following two indexe have been taken into account: delay index - departure; headway index. Such indexe, which if uitably cutomied may be utilied for both railway and metro ytem, allow the etimation of ervice quality a far a operating characteritic are concerned. They coincide with the one propoed by UITP, but their analytical expreion have been uitably revied in order to be applied in different cenario. For a generic index X, the relationhip for the meaure of the average value XM, of the RMS value XRMS and of the tandard deviation <Jx are preented; in particular, the lat one give probabilitic information about a population tarting from a meaure performed on a limited number of element, being about 68% the probability that X aume a value in the range %,-<% X^ +0*-) ifxi uppoed normally ditributed. 4.1 Delay index D (departure) The delay index D i defined a: D = tdep_real ~ tdep_ch 0) where:
468 Urban Tranport and the Environment for the 21t Century tdep_reai = real departure time, meaured in point d of Figure 2 tdep ch ~ cheduled departure time The average value D^ i: The RMS value DRMS i: n The tandard deviation cr^ i: -1 \6= where: Dk = departure delay index for k-th train n = number of oberved train 4.2 Headway index The headway indexi defined a: f= fa _ fi ($\ where: hreai = real headway hch ~ cheduled headway The average value f^ i: 1 JL The RMS value f^ i: (7) The tandard deviation c^i: I i ( n " X I n f 7? ' L,Jk V f2 ~*Vm nf2 ~ - \ J\JRMS f2 ~ Jm fl n-l\k=i ) Vrc-yv (8) where:
Urban Tranport and the Environment for the 21t Century 469 fk n = headway variation for k-th train = number of oberved train In order to perform the impact analyi on traffic regularity in Milan Metro due to the introduction of MARCO, a collection activity of hitorical data ha been carried out, taking into account the following condition: winter timetable (September-October); peak evening hour (17.00-18.50); which repreent both the analogou period when the field tet will be executed and the time interval when the traffic diturbance may be highly probable. In particular, the data collection i related to the following event: arrival at the terminu; departure from the terminu. The firt cla of data deal with the definition of diturbance typology (frequency and duration), while the econd one i ueful to characterie the previouly mentioned indicator before the introduction of MARCO tool. Moreover, they allow a better knowledge of the arrival delay pattern (for algorithm refinement purpoe) a well a the actual terminu regulation policy. The ample ize required to be ignificant will be dimenioned later by experimental way. At preent a good tarting point may be a ample of 300 train paing through the terminu (about 10 day of peak hour operation). The value of hitorical performance indexe will be calculated and analyed by mean of adequate tatitical method in order to make poible a comparion with the analogou indexe, imilarly collected during the tet activity of MARCO demontrator. The final releae of the performance indexe to be utilied for the evaluation of Milan Metro application will be further refined, taking into account the final verion of the optimiation trategy implemented in the demontrator. 5 Concluion In thi paper the author have preented the evaluation framework of EU Telematic project MARCO. In particular, tarting from the general objective propoed by the project, they have highlighted the evaluation activity which will be carried out in the Milan Metro verification ite, where a demontrator will be implemented and executed utiliing the data coming from the field operation. To thi aim the et of indicator,
470 Urban Tranport and the Environment for the 21t Century which will be probably utilized for impact analyi on traffic performance of the terminu, have been propoed. In the next month the development of the demontrator will be completed and the verification phae will tart. Moreover, thank to the promiing reult of the current project, a new EU Telematic project, COMBINE, i next to tart. Thi new project, till managed by Adtranz Italy and evaluated by UGDIE, will deal with the conflict detection and reolution problem in metrorail application in preence of moving block baed ignalling ytem. Reference [1] Freddy De Vilder, MARCO, A European project to develop tool for conflict detection and reolution in railway and metro application, In Proceeding of 8* IFAC Sympoium on Tranportation Sytem, Chania, Greece, June 16-18, 1997. [2] Zhang, X. and Kompfner, P., Common Guideline for Aement of ATT Pilot, CORD Deliverable AC02-Part 6, Bruel, December 1993. [3] Keller, H. (editor), Impact Aement and Evaluation in Advanced Tranport Telematic, Proceeding of ATRACC3 Coure, SODIT S.A., Labege, France, November 1993.